Variable condenser



Feb. 12, 1929' P. F. SHNER'S VARIABLE CONDENSER Filed Aug. 6, 1925 Patented Feb. 12, 1929i.

UNITED STATES 1,702,061 PATENT OFFICE.

PAUL F. SHIV'ERS, OF WABASH, INDIANA, lASSIGNOR TO WEBSTER ELECTRIC COMU- lPANY, OF RACINE, WISCONSIN, A CORPORATION 0F WISCONSIN.

, vAmABLE COND-ENSER.

Application l'ed August v6, 1923. Serial No. 655,818.

My invention relates to variable condensers, and contemplates the provision of Y a device of this class comprising but two sets rof condenser plates, but whichv is, nevertheless, capa-ble of affording the very fine adjustment of capacity necessary in connection with the circuits of many radio receiving sets. lVhile thecondenser of my invention is particularly suitable for radio work, 1t

should* be understood t-hat its uselis by no means so limited. v

Briefly stated, my invention contemplates moving one of'two sets of lcondenser plates around one center toA effect the gross adjustment of capacity, and thenrmoving oneof said sets around a .dili'erent center to effect the'fine adjustment. f VAs a detailed description of my invention will bestrbe understood when read in connection with an illustrative drawing, I shall proceed to a description of the accompanying drawing, in which d Fig.V 1 is aV perspective, partly in section, of one embodiment of my invention;v

Fig. 2 isa side view, partly in section, of amodied embodiment of the invention, and

. Y Fig. 3 is afragmentaryview taken on line 3 3 of Fig. 2.

. Referring first to Figure 1, reference characters and11 indicate supporting plates of insulating material whichvare connected by a bolt 12. Bolt 12 lcarries a Vsetvof condenser plates v13-18,1each of which has its l other end apertured to receive a bolt 14.

, At l5 isillustrated a plate of insulating material which, similarly to.V the plates 13-`13, has onelend journaled upon bolt 12,

and' is apertured at its other end Vto 'receiveA the bolt 14. Washers 16-16 and 17 -17 carried by the bolts12 and 14, respectively, serve to space the plates 13A-13 from plate 15' and from each other. APlate is provided with an elongated aperture 18, the purpose of whichwill presently appear.

Rotatably supported in plates 10 and 11 is a metal shaft 19 provided with an operating button 20 andhaving xed thereto a cam or eccentric collar 21, which occupies the elongated slot 18 of the plate 15. Disposed around shaft 19 is a movable quill shaft 22 which carries a plurality of condenser plates 23-'23, which are adapted to be movedinto the spaces between plates 13-13 by manipulating button 24 Xed to said quill shaft. Plates 23-23 are clamped between and spaced by manipulating button v plates 13-13 and-23-23.

a plurality of washers 25-25. If desired, button 24 may be provided with the usual dial, not shown, adapted to cc-operate with an index carried by a panel board, or other suitable support, also not shown.

The condenser just described may be included in circuit by connecting one conductor of the latter with either of the bolts 12 or 14 which are in contact with conductor plates 13 13, and by connecting another conductor with a brush spring 26 which bears against shaft 19,', electrical connection between brush 26 and conductor plates 23- 23 being afforded through shafts 19 and 20.

In using the condenser, the principal or gross adjustment of capacity is obtained by 24 to move the plates 28-23 relatively to the plates 13-13. The latter plates may be considered stationary plates, in so far as the gross adjustment is concerned. A more delicate adjustment is then obtained by manipulating button 20, the cam 21 co-operating with plate 15 to move the latter and the condenser plates 13-13, relatively to plates 23-23, around an axis represented by bolt 12 to vary by extremely small increments the relation between the In this type of condenser, the plates 23-28 may be regarded as the stationary plates, so far as the fine adjustment is concerned.

In Figs. 2 and 3,-I have illustrated a modified embodiment of my invent-ion wherein one set of condenser plates is moved around different axes to accomplish both the gross and ne capacity adjustments. This embodiment of my invention comprises a pair of insulating plates 3() and 30il connected by metal bolts 31-31 which carry a plurality of fixed condenser plates 82-32which are held in properly spaced relation by washers 33--33. Plates 32-82 may be of substantially the same shapeas the plates 13-18 of the device illustrated inFig. 1. Supporting plate a is here shown as being mounted upon a panel board or other suitable support 34 by screws 35-35 which co-operate with tapped lugs 36-36 carried by the plate 80a.

Plate 30a provides a relatively long bearing 37 for a bearing sleeve or hub 88 which is capable ot rotary movement in said bearing 37, but is held against longitudinal displacement by a. screw 39 which engages in an annular groove 40 formed in the periphery of said hub or sleeve 38. Journaled in the sleeve or hub 38 and extending eccentrically there,

through is a metal shaft 4l provided With an operating button 42, which may be equipped WithV the usual dial 43. Dial 43 is here shown as being spaced slightly from the front face of the panel board 34 to accommodate a lever 44 Which is providedat one end with anop-V` erating handle l45, and has its lother end rigidly secured by screws tothe bearing sleeve or hub 38, as is most clearly illustrated in Fig. 3. The panel or' other support 34 is,

' of course, suitably apertured to accommodate shaft 41 rand lever 44.

It Will be noted that shaft 4l has its sole bearing in sleeve or hub 33,'thesaid shaft extending freely through an enlarged aper@ ture in frame plate 3G and being engaged by a brush spring 46 which may constitute one of the terminals ofthe condenser. Shaft 4l has I fixed thereto a plurality of condenser plates 47 Which are adapted to be moved inproximity to and in the spaces. between thestationary condenserplates 32-32- Plates 47--47 are conveniently held suitably spaced by Washers 43u48. lt will be understood that plates 47 47 may be of substantially the same shape as the plates 213-23 of the condenser illustrated in Fig. l.

' The condenser illustrated in Figs. 2 and 3 u may be'included in a circuit by connecting one of the conductors of the latter with brush 'spring-46, and by connecting another conductor lWithV either of the bolts 31-431. The prin cipal or gross adjustment of capacity is `accomplished by manipulating button 42 to rotate the movable `plates 47-*47 relatively to the stationary plates`32-4-32. The more delicate adjustmentmay then be accomplished by manipulating the lever '44 to shift the axis of the shaft 41, and thereby, by small increments, vary the' relation of the movable and stationary condenserplates.

' Having thus illustrated and:V described two i practical embodiments of my invention, what I claim is new and desire to secure'by Letters Patent'of the United States is: A Y

Y l'. itl condensercoinprising a plurality of sets of elements movable relatively to each other to' varythe capacity of 4said condenser, means for movingthe elements of one set relatively tothe others around a given' axis to effect a" gross adjustment, and meansA for mov# v ing the'axis of the elements of one group lat# means carried by one of erally, While maintaining the elements of said group 'substantially parallel to those of the other group to effect a fine adjustment.

2. A condenser comprising a` plurality of Yfixed element-s mounted lfor rotation adjacent said fixedl elements to vary the capacity ,of said condenser, a shaft for supporting said movable elements and means for moving said 4shaft in an arc VWhile maintaining said shaft substantially parallel to its initial position.

' 3. A condensercomprising a plurality ofv fixed elements mounted for'rotation adjacent said fixed elements to vary the Vcapacity ofV said condenser, a.V shaft for supporting saidv l movableV elements, and a concentric'bearing V.forsaid shaft for supporting the saine and moving `said shaft atright angles'to its axis to secure a fine adJustment.V e 4. 'A condenser comprising set-s of elements movable relativelyfto'each other tovary theV capacity of said condenser, an actuating ele-V ment operatively 'connected to one of said set-s Y to movethe same relativelyto another set to l effect aj gross adjustment 'of capacity, a second actuating element adapted to move one set relatively to another to effect a'ne adjustment of capacity and common indicating ments.A l 1 'Hoffi condenser'comprising a support, a plurality of xed elements carried vby' said support, a shaft, a plurality of movableelementsf carried by said shaft, an elongated bearing for said shaft,said bearing being eccentrically and rotatablysupported on said support, and an actuating lever for saidbearing for moving said shaft to various positions said `actuating elesupport',`an actuating lever for said bearing l for moving saidshaft lto various positions" parallel to 'its axis, and a dialcarried said shaft for indicating adjustment-'of said -c'ondenser with said lever. f f

In witness'whereof, I' hereunto. subscribe myname this l'day of July, 1923.

y y rant nsnivnas."

ioo 

